Title

Author

Defense Date

2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Psychology

First Advisor

Kirk Warren Brown

Abstract

Mindfulness – a receptive attentiveness to present experience – has been shown to promote more adaptive emotion regulation (Brown et al. 2008). Additionally, dispositional mindfulness has been shown to predict reduced cortisol response to social stressors (Brown et al, in press) and mindfulness training has been shown to promote more adaptive cardiac functioning at rest (Ditto et al., 2006; Tang et al., 2009; Telles et al., 2005; Zeidan et al., 2010) and in response to social stressors (Kemeny et al., 2012). To better understand the regulatory potential of a mindful disposition on cardiovascular functioning in healthy adult participants (N = 63), the study examined the role of dispositional mindfulness in predicting cardiovascular responses to a laboratory social evaluative threat called the Trier Social Stress Task (TSST; Kirschbaum, et al., 1993). Repeated measures multilevel linear modeling tested main effects of a mindful disposition on a variety of cardiovascular outcomes as well as interactive effects between mindfulness and time on these outcomes. Results showed that mindfulness predicted increased heart rate variability (HRV) across the time span, from baseline to recovery. There were also interactions between mindfulness and time on several dependent variables. Specifically, higher mindfulness predicted decreased heart rate reactivity during the TSST, faster recovery in total HRV, as well as reduced rebound effects during the initial recovery phase for high frequency HRV, low frequency HRV, and the LF/HF ratio. These results, however, were not significant above and beyond the significant relations between rumination, depressive symptoms, and trait anxiety and cardiovascular function. The results lend support to the stress-related regulatory potential of mindfulness, and suggest that this quality of attention may enhance cardiovascular functioning under stress. Further research is needed to examine how mindfulness may buffer the role of such vulnerability factors as rumination, depressive symptoms, and anxiety in predicting stress-related cardiovascular responses to social stress.